If your profile is correct then I am not sure how flying in a specialist area such as you do and mainstream airline flying can be compared. They are chalk and cheese. As is the screening, assessment and interview process at our outfits. Specialist jobs such as yours invariably involve knowing someone and a one on one interview with the chief pilot. Jobs like yours are often never even advertised.
Getting into an airline involves having the right sort of CV, saying the right things, timing it right and getting the CV onto the right persons desk. You might one day bump into the chief pilot if your lucky. The airlines will get thousands of applications, screen out the majority and call in those that meet set criteria which often includes where they trained. It is the sad reality of life that if you go to a low profile school then you may not pass go and you will never know why you did not get called.